plugins/mod_saslauth.lua

   1
   2 local st = require "util.stanza";
   3 local send = require "core.sessionmanager".send_to_session;
   4 local sm_bind_resource = require "core.sessionmanager".bind_resource;
   5 local jid
   6
   7 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
   8 local t_concat, t_insert = table.concat, table.insert;
   9 local tostring = tostring;
  10
  11 local log = require "util.logger".init("mod_saslauth");
  12
  13 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  14 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  15 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  16
  17 local new_sasl = require "util.sasl".new;
  18
  19 local function build_reply(status, ret)
  20         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  21         if status == "challenge" then
  22                 reply:text(ret or "");
  23         elseif status == "failure" then
  24                 reply:tag(ret):up();
  25         elseif status == "success" then
  26                 reply:text(ret or "");
  27         else
  28                 error("Unknown sasl status: "..status);
  29         end
  30         return reply;
  31 end
  32
  33 local function handle_status(session, status)
  34         if status == "failure" then
  35                 session.sasl_handler = nil;
  36         elseif status == "success" then
  37                 session.sasl_handler = nil;
  38                 session:reset_stream();
  39         end
  40 end
  41
  42 local function password_callback(jid, mechanism)
  43         local node, host = jid_split(jid);
  44         local password = (datamanager.load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  45         local func = function(x) return x; end;
  46         if password then
  47                 if mechanism == "PLAIN" then
  48                         return func, password;
  49                 elseif mechanism == "DIGEST-MD5" then
  50                         return func, require "hashes".md5(node.."::"..password);
  51                 end
  52         end
  53         return func, nil;
  54 end
  55
  56 function do_sasl(session, stanza)
  57         local text = stanza[1];
  58         if text then
  59                 text = base64.decode(text);
  60                 if not text then
  61                         session.sasl_handler = nil;
  62                         session.send(build_reply("failure", "incorrect-encoding"));
  63                         return;
  64                 end
  65         end
  66         local status, ret = session.sasl_handler:feed(text);
  67         handle_status(session, status);
  68         session.send(build_reply(status, ret));
  69 end
  70
  71 add_handler("c2s_unauthed", "auth", xmlns_sasl,
  72                 function (session, stanza)
  73                         if not session.sasl_handler then
  74                                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  75                                 do_sasl(session, stanza);
  76                         else
  77                                 error("Client tried to negotiate SASL again", 0);
  78                         end
  79                 end);
  80
  81 add_handler("c2s_unauthed", "abort", xmlns_sasl,
  82         function(session, stanza)
  83                 if not session.sasl_handler then error("Attempt to abort when sasl has not started"); end
  84                 do_sasl(session, stanza);
  85         end);
  86
  87 add_handler("c2s_unauthed", "response", xmlns_sasl,
  88         function(session, stanza)
  89                 if not session.sasl_handler then error("Attempt to respond when sasl has not started"); end
  90                 do_sasl(session, stanza);
  91         end);
  92
  93 add_event_hook("stream-features",
  94                                         function (session, features)
  95                                                 if not session.username then
  96                                                         t_insert(features, "<mechanisms xmlns='urn:ietf:params:xml:ns:xmpp-sasl'>");
  97                                                                 t_insert(features, "<mechanism>PLAIN</mechanism>");
  98                                                         t_insert(features, "</mechanisms>");
  99                                                 else
 100                                                         t_insert(features, "<bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'><required/></bind>");
 101                                                         t_insert(features, "<session xmlns='urn:ietf:params:xml:ns:xmpp-session'/>");
 102                                                 end
 103                                                 --send [[<register xmlns="http://jabber.org/features/iq-register"/> ]]
 104                                         end);
 105
 106 add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 107                 function (session, stanza)
 108                         log("debug", "Client tried to bind to a resource");
 109                         local resource;
 110                         if stanza.attr.type == "set" then
 111                                 local bind = stanza.tags[1];
 112
 113                                 if bind and bind.attr.xmlns == xmlns_bind then
 114                                         resource = bind:child_with_name("resource");
 115                                         if resource then
 116                                                 resource = resource[1];
 117                                         end
 118                                 end
 119                         end
 120                         local success, err = sm_bind_resource(session, resource);
 121                         if not success then
 122                                 local reply = st.reply(stanza);
 123                                 reply.attr.type = "error";
 124                                 if err == "conflict" then
 125                                         reply:tag("error", { type = "modify" })
 126                                                 :tag("conflict", { xmlns = xmlns_stanzas });
 127                                 elseif err == "constraint" then
 128                                         reply:tag("error", { type = "cancel" })
 129                                                 :tag("resource-constraint", { xmlns = xmlns_stanzas });
 130                                 elseif err == "auth" then
 131                                         reply:tag("error", { type = "cancel" })
 132                                                 :tag("not-allowed", { xmlns = xmlns_stanzas });
 133                                 end
 134                                 send(session, reply);
 135                         else
 136                                 local reply = st.reply(stanza);
 137                                 reply:tag("bind", { xmlns = xmlns_bind})
 138                                         :tag("jid"):text(session.full_jid);
 139                                 send(session, reply);
 140                         end
 141                 end);
 142
 143 add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 144                 function (session, stanza)
 145                         log("debug", "Client tried to bind to a resource");
 146                         send(session, st.reply(stanza));
 147                 end);